UNIT – II PLANT LAYOUT MEANING: The efficiency of production depends on how well the various machines; production facilities and employee’s amenities are located in a plant. Only the properly laid out plant can ensure the smooth and rapid movement of material, from the raw material stage to the end product stage. Plant layout encompasses new layout as well as improvement in the existing layout. DEFINITION: A plant layout can be defined as follows: Plant layout refers to the arrangement of physical facilities such as machinery, equipment, furniture etc. with in the factory building in such a manner so as to have quickest flow of material at the lowest cost and with the least amount of handling in processing the product from the receipt of material to the shipment of the finished product. According to Riggs, “the overall objective of plant layout is to design a physical arrangement that most economically meets the required output – quantity and quality.” According to J. L. Zundi, “Plant layout ideally involves allocation of space and arrangement of equipment in such a manner that overall operating costs are minimized.
OBJECTIVES OF GOOD PLANT LAYOUT: An efficient plant layout is one that can be instrumental in achieving the following objectives: a) Proper and efficient utilization of available floor space b) To ensure that work proceeds from one point to another point without any delay c) Provide enough production capacity. d) Reduce material handling costs e) Reduce hazards to personnel f) Utilise labour efficiently g) Increase employee morale h) Reduce accidents i) Provide for volume and product flexibility j) Provide ease of supervision and control
k) Provide for employee safety and health l) Allow ease of maintenance m) Allow high machine or equipment utilization n) Improve productivity
TYPES OF LAYOUT plant layout may be of four types: (a) Product or line layout (b) Process or functional layout (c) Fixed position or location layout (d) Combined or group layout
(a) Product or line layout: •
machines and equipments are arranged in one line depending upon the sequence of operations required for the product.
•
Also called as line layout
•
The materials move form one workstation to another sequentially without any backtracking or deviation.
•
machines are grouped in one sequence
•
the output of one machine becoming input of the next
•
The raw material moves very fast from one workstation to other stations with a minimum work in progress storage and material handling.
Advantages: Product layout provides the following benefits: a) Low cost of material handling, due to straight and short route and absence of backtracking b) Smooth and uninterrupted operations c) Continuous flow of work
d) Lesser investment in inventory and work in progress e) Optimum use of floor space f) Shorter processing time or quicker output g) Less congestion of work in the process h) Simple and effective inspection of work and simplified production control i) Lower cost of manufacturing per unit
Disadvantages: Product layout suffers from following drawbacks: a. High initial capital investment in special purpose machine b. Heavy overhead charges c. Breakdown of one machine will hamper the whole production process d. Lesser flexibility as specially laid out for particular product.
Suitability: Product layout is useful under following conditions: 1) Mass production of standardized products 2) Simple and repetitive manufacturing process 3) Operation time for different process is more or less equal 4) Reasonably stable demand for the product 5) Continuous supply of materials
(b) Process layout: •
machines of a similar type are arranged together at one place.
•
The processor functional layout is followed from historical period.
•
It evolved from the handicraft method of production
•
The work has to be allocated to each department in such a way that no machines are hosen to do as many different job as possible
•
The work, which has to be done, is allocated to the machines according to Loading schedules with the object of ensuring that each machine is fully loaded
•
suitable for job order production involving non-repetitive processes and customer specifications and non-standardized products
• The grouping of machines according to the process has to be done keeping in mind the following principles a. The distance between departments should be as short as possible for avoiding long distance movement of materials b. The departments should be in sequence of operations c. The arrangement should be convenient for inspection and supervision Advantages: Process layout provides the following benefits a) Lower initial capital investment in machines and equipments. There is high degree of machine utilization, as a machine is not blocked for a single product b) The overhead costs are relatively low c) Change in output design and volume can be more easily adapted to the output of variety of products d) Breakdown of one machine does not result in complete work stoppage e) Supervision can be more effective and specialized f) There is a greater flexibility of scope for expansion. Disadvantages: Product layout suffers from following drawbacks a. Material handling costs are high due to backtracking b. More skilled labour is required resulting in higher cost. c. Time gap or lag in production is higher d. Work in progress inventory is high needing greater storage space e. More frequent inspection is needed which results in costly supervision Suitability: Process layout is adopted when 1. Products are not standardized 2. Quantity produced is small 3. There are frequent changes in design and style of product 4. Job shop type of work is done 5. Machines are very expensive
(c) Fixed Position or Location Layout
• •
•
the major product being produced is fixed at one location. Equipment labour and components are moved to that location All facilities are brought and arranged around one work center This type of layout is not relevant for small scale entrepreneur.
Advantages: Fixed position layout provides the following benefits a) It saves time and cost involved on the movement of work from one workstation to another. b) The layout is flexible as change in job design and operation sequence can be easily incorporated. c) It is more economical when several orders in different stages of progress are being executed simultaneously. d) Adjustments can be made to meet shortage of materials or absence of workers by changing the sequence of operations. Disadvantages: Fixed position layout has the following drawbacks a. Production period being very long, capital investment is very heavy b. Very large space is required for storage of material and equipment near the product. c. As several operations are often carried out simultaneously, there is possibility of confusion and conflicts among different workgroups. Suitability: The fixed position layout is followed in following conditions 1. Manufacture of bulky and heavy products such as locomotives, ships, boilers, generators, wagon building, aircraft manufacturing, etc. 2. Construction of building, flyovers, dams. 3. Hospital, the medicines, doctors and nurses are taken to the patient (product).
(d) Combined layout •
Certain manufacturing units may require all three processes namely intermittent process (job shops), the continuous process (mass production shops) and the representative process combined process [i.e. miscellaneous shops].
•
manufacturing concerns where several products are produced in repeated numbers with no likelihood of continuous production, combined layout is followed.
PRINICIPLES OF GOOD PLANT LAYOUT:
1. Maximum flexibility - The plant layout should not be rigid and permanent. If the need arises, the plant layout should be able to change itself without being expensive. 2. Maximum coordination - The layout of the plant should such that all of its resources and workforce can be observed and evaluated at all points in time. This helps in better supervision of work and helps in increasing both effectiveness and safety. 3. Maximum visibility- The layout should visible to all the workers in the organization(For Example: Visibility means how will it spread to everyone in organization. For Eg: "CEO actions are visible to all", means everyone in organization will know about CEO actions.) 4. Minimum Movement - The less the movement of men, machines and materials, the less will be the cost of production. Thus, minimum movement of theses resources will provide cost efficiency. 5. Minimum Discomfort- The layout should reduce the uncomfortable for the workers in the organization 6. Minimum Handling - The ineffective handling of materials leads to a rise in cost. Materials should be handled in stacks and transferred in one go. Handling of a material twice in the same direction must be avoided. 7. Safety Aspects - The environment of the plant should be safe for the workers as well as the machines. There should be fire extinguishers and fire exits placed strategically. There should be minimum contact of the labour to toxic chemicals and environment. 8. Efficient Process Flow-A good layout is one that makes the materials to move in forward direction towards the completion stage i.e. there should not be any backtracking. 9. Identification-Every plant layout should have identification to identify
FACTORS INFLUENCING LAYOUT 1. Plant Location:
• •
plant layout and location are interrelated with one another The nature and size of the building determines the floor space available for layout. While designing the special requirements, e.g. air conditioning, dust control, humidity control etc. must be kept in mind.
2. Nature of Product: • •
product layout is suitable for uniform products whereas process layout is more appropriate for custom-made products. Depending upon the sequence of operation and the nature of the product plant layout is decided.
3. Type of Industry:
• • •
Product layout is suitable for continous production Process layout is suitable for intermittent production Synthetic industry, analytical industry, conditioning industry and extraction industry
4. Plant Environment: • •
Heat, light, noise, ventilation and other aspects should be duly considered, e.g. paint shops and plating section should be located in another hall so that dangerous fumes can be removed through proper ventilation etc Adequate safety arrangement should also be made
5. Spacial Requirement: •
The space of a layout is used for the labourers to work for machines to perform operations for storage of raw material and finished the space is allocated in a current layout
6. Repairs and Maintainence: •
machines should be so arranged that adequate space is available between them for movement of equipment and people required for repairing the machines.
7. Balance: •
The plant layout has to ensure balance between the number of processes and number of machines the capacity of each machine is considered to avoid overloading and maintainence.
8. Management Policies: •
The management has to considered the following points by formulating policy with regard to plant layout.
Size of the product Delivery schedule Employee facility No. of equipment and facility Productivity
MATERIAL MANAGEMENT MEANING: Material management is the branch of logistics that deals with the tangible components of a supply chain. Specifically, this covers the acquisition of spare parts and replacements, quality control of purchasing and ordering such parts, and the standards involved in ordering, shipping, and warehousing the said parts. •
Defined as the art and science of moving, packing and storing of substances in any form. – Creation of time and place utility – Movement and storage of material at the lowest possible cost through the use of proper methods and equipments. – Lifting, shifting and placing of materials which effect a saving in money, time and place – Art and science of conveying, elevating, positioning, transporting, packaging and storing of materials
ADVANTAGES OF GOOD MATERIAL HANDLING: • •
• •
• • •
• •
Increased efficiency of production Better utilization of floor space Simplified handling activities Better equipment utilization, less idle time Reduced in-process time Reduced in-process inventory More efficient utilization of work force Reduced product damage Reduced walking distance
• • • •
Minimal accident hazards Basis for an efficient layout Faster supervision Minimal back tracking
•
Smooth production flow
•
Improved scheduling process
•
Reduced crowded conditions
•
Better house keeping
•
Logical work sequencing
PRINCIPLES OF MATERIAL HANDLING:
1. PLANNING PRINCIPLE:
•
Plan to meet requirements efficiently, but maintain flexibility for contingencies
•
Large-scale material handling projects usually require a team approach.
•
Material handling planning considers every move, every storage need, and any delay in order to minimize production costs.
•
The plan should reflect the strategic objectives of the organization as well as the more immediate needs.
2. SYSTEM PRINCIPLE:
•
Coordinate and integrate receiving, inspection, storage, product, asssembly, packaging, warehousing and distribution systems.
•
Information flow and physical material flow should be integrated and treated as concurrent activities.
•
Methods should be provided for easily identifying materials and products, for determining their location and status within facilities and within the supply chain.
3. MATERIAL FLOW PRINCIPLE
•
Manage materials effectively
• •
Provide an operation sequence and equipment layout optimizing material flow. to ensure national planning, especially for scarce resources, and to allow forecasting
•
improve total quality management
4. SIMPLIFICATION
•
simplify and eliminate handling steps if possible
•
simplify handling by reducing, eliminating, or combining unnecessary movement and/or equipment.
•
Four questions to ask to simplify any job: Can this job be eliminated? If we can’t eliminate, can we combine movements to reduce cost? (unit load concept) If we can’t eliminate or combine, can we rearrange the operations to reduce the travel distance? If we can’t do any of the above, can we simplify?
5. SPACE UTILISATION
•
. The better we use our building cube, the less space we need to buy or rent.
•
Racks, mezzanines, and overhead conveyors are a few examples that promote this goal.
6. SAFETY PRINICIPLE
•
Provide safe methods and equipment. Follow safety codes
• •
proper work practices, equipment, and controls can help reduce workplace accidents involving the moving, handling, and storing of materials.
7. UNIT LOAD MATERIAL • •
Handle product in as large a unit load as practical. Unit loads should be appropriately sized and configured at each stage of the supply chain.
•
The most common unit load is the pallet cardboard pallets plastic pallets wooden pallets steel skids
8. EQUIPMENT SELECTION PRINCIPLE •
Why? What? Where? When? How? Who?
9. AUTOMATION PRINCIPLE
•
Material Handling operations should be mechanized and/or automated where feasible to improve operational efficiency, increase responsiveness, improve consistency and predictability, decrease operating costs.
•
ASRS is a perfect example. (An automated storage and retrieval system (ASRS or AS/RS) consists of a variety of computer-controlled methods for automatically placing and retrieving loads from specific storage locations.)
10. STANDARDISATION PRINCIPLE • •
Standardize handling methods and equipment wherever possible. standardize handling methods as well as types and sizes of handling equipment
•
too many sizes and brands of equipment results in higher operational cost.
•
A fewer sizes of carton will simplify the storage.
11. FLEXIBILITY PRINCIPLE •
Use methods and equipment which can perform a variety of tasks under a variety of operating conditions.
12. MOTION PRINCIPLE •
Materials and tools should be located to permit the best sequence of motions
•
Tools, materials and controls should be located close to the point of use.
13. IDEAL TIME 14. MAINTAINENCE PRINCIPLE • •
Prepare a plan for preventive maintenance and scheduled repairs on all material handling equipment Pallets and storage facilities need repair too.
15. CONTROL PRINCIPLE •
Use material handling activities to improve control of production, inventory, and order handling.
•
Good materials handling practice can effect savings is by making the control of goods easier particularly in continuous manufacturing, where all operations are “tied together” by the materials handling plan.
16. CAPACITY PRINCIPLE •
use handling equipment to help achieve desired production capacity
•
i.e. material handling equipment can help to maximize production equipment utilization • Example: A punch press can cycle every 0.03 minute, but our time standard for manually loading and unloading this press is only 300 pieces per hour. Press capacity = 60 min / 0.03 = 2000 pieces/hr Utilization = 300 / 2000 = 15% Should we buy a new press? If we can purchase a coil-feeding material handling system, we could approach 100% press utilization.
